Sponge mops are generally known wherein a flat rectangular sponge or sponge like material is mounted on a base plate holder which is hinged to a flat pressure plate so that the two plates can be folded towards each other to expel excess liquid from the sponge.
Currently, some sponge mops also include a scrub strip generally made of a cloth-like textured material which is attached by an adhesive or conventional means to the sponge, allowing the user to perform a more abrasive action on a surface. Disadvantageously, present sponge mops heads are less effective when a scrub strip is present because a conventional flat pressure plate cannot fully compress the sponge.
In addition, the force of the pressure plate during wringing is destructive to the scrub strip, wearing it down and/or delaminating the strip from the sponge. For example, U.S. Pat. No. 2,774,091 issued to Greenleaf describes a curved wringer plate in the figures and in Col. 3, lines 58-64 to accommodate the bulk-up of a sponge during the wringing by longitudinal rollers. Despite the stated purpose of the curvature, the curved wringer plate in Greenleaf reduces the effectiveness of the wringing operation of the sponge. Moreover, the curved wringer plate of Greenleaf can not protect a scrub strip from tearing or delaminating during wringing. Therefore, there exists a need for wringer plates which will protect the scrub strip during wringing operations.
Another disadvantage with conventional sponge mops is that the sponge refill cartridges are often difficult to remove and replace. For example, U.S. Pat. No. 4,509,224 to Batchelor, utilizes a combination of screw nuts, shank heads and locking holes for connecting a sponge backing plate to a mop head. Disadvantageously, it appears from the Batchelor patent that each screw head has to be removed from each shank before replacing the sponge and then returned while attaching the new sponge to the mop.
Accordingly, it is an object of the present invention to provide a sponge mop head which will not damage a scrub strip during the wringing of the sponge.
It is another object of the present invention to provide a refillable sponge mop head in which the sponge refill cartridge is conveniently removed and replaced.